function invertCheckboxes()
{
	var multiActionForm = document.getElementById('FreeReport-form');
	
	var doSelect=false;
	for (i=0; i<multiActionForm.elements.length; i++) if(multiActionForm.elements[i].type == 'checkbox')
	{
		if(!multiActionForm.elements[i].checked) doSelect=true;
	}
	
	for (i=0; i<multiActionForm.elements.length; i++) if(multiActionForm.elements[i].type == 'checkbox')
	{
		multiActionForm.elements[i].checked = doSelect;
	}
}